Diagnostic device for a liquid sample

ABSTRACT

A diagnostic device for a liquid sample comprising, a receptacle having a cavity containing a culture medium, and means for establishing communication with the sample. The device has pump means for withdrawing and expelling liquid, and valve means for separately establishing communication of the establishing means and the receptacle with the pump means, in order that a liquid sample may be withdrawn by the pump means through the establishing and valve means and expelled by the pump means through the valve means into the receptacle for inoculation of the culture medium.

This is a division of application Ser. No. 495,978, filed Aug. 29, 1974,now U.S. Pat. No. 3,952,729.

BACKGROUND OF THE INVENTION

The present invention relates to diagnostic devices, and moreparticularly to a device for diagnosing a liquid sample.

It is frequently desirable to determine the presence of bacteria in bodyfluids of a patient, such as blood or urine, for purposes of diagnosis.For example, a major problem confronting hospitals today is thedetermination of urinary tract infections. Although chills, fever,dysuria and frequency of urination may indicate infection, the incidenceof asymptomatic urinary tract infection has been shown to be a commonoccurence. This asymptomatic infection is clinically diagnosed bytesting for bacteriuria, which literally means the presence of bacteriain the urine. Clean voided urine from normal individuals generallycontains microorganisms, which are indigenous residents of the urethra.Urine in the bladder, on the other hand, is ordinarily sterile, and thepresence of any bacteria in the upper urinary tract is consideredabnormal. Significant bacteriuria is a term that has been used todescribe the numbers of bacteria in voided urine that exceed the numbersusually due to contamination from the anterior urethra and are in therange of the bacterial titers usually found in infected bladder urine.It has been established that a guideline for determination of bladderbacteriuria is the presence of 100,000 or more bacteria per milliliterin whole voided urine, although 70 to 85% of most cases of bacteriuriaare characterized by counts of over 1,000,000 organisms per milliliter.

Since the presence of bacteriuria may be determined by the number oforganisms in the urine, it has been found advantageous to use culturemedia for determining the number of bacteria in a sample of the urine.Presently hospitals and laboratories frequently collect a sample of bodyfluid, such as urine or blood, in a receptacle, and transfer thecollected fluid from the receptacle to a culture bottle. However, thetime lag encountered with this type of procedure presents a recurrentproblem, and may cause unreliability in the test results. For example,urine presents an ideal growth medium for microorganisms, and certainspecies of bacteria may double in number in as little as 20 minutes.Accordingly, the assessment of urine for bacteriuria should be madeimmediately after the specimen is voided, since a sufficient time lagmakes a distinction between significant infection and an overgrowth ofcontaminants impossible. Likewise, other microorganisms are so sensitiveto their environment that they are unable to survive the delay, and theinoculation media will not present a true picture for the diagnostician.Thus, it is desirable to reduce the delay between taking the sample ofthe body fluid and the subsequent inoculation of culture medium with thesample, as well as preventing contamination of the sample.

SUMMARY OF THE INVENTION

A principle feature of the present invention is the provision of adevice of simplified construction for diagnosing the presence ofbacteria in a liquid sample.

The diagnostic device of the present invention comprises a receptaclehaving a cavity containing a culture medium, and means for establishingcommunication with the sample. The device has pump means for withdrawingand expelling liquid, and valve means for separately establishingcommunication of the establishing means and the receptacle with the pumpmeans.

Thus, a feature of the invention is that the liquid sample may bewithdrawn by the pump means through the establishing and valve meanspreparatory to inoculation of the culture medium.

Another feature of the invention is that the withdrawn sample may beexpelled by the pump means through the valve means into the receptaclefor inoculation of the culture medium.

A further feature of this invention is that the device permitsinoculation of the medium with the sample in a simplified manner.

A feature of the invention is that the device permits a closed-systemtransfer of virtually any body fluid, human or animal, into the culturemedium.

Thus, another feature of the invention is that the culture medium isinoculated with the liquid sample without contamination of the sample.

Yet another feature of the invention is that the culture medium isinoculated substantially immediately after withdrawing the sample.

A feature of the invention is that in one embodiment the establishingmeans comprises a hollow needle for penetrating a source of liquidsample, such as urine in a catheter.

A further feature of the invention is that the establishing meanscomprises an elongated hollow member communicating with the valve meansand having a swab adjacent an end distal the valve means, in order tointroduce and spread a sterile suspension liquid for the sample at thesample site.

Still another feature is the provision of a method of preparing a samplefor diagnosis.

Further features will become more fully apparent in the followingdescription of the embodiments of this invention and from the appendedclaims.

DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a diagnostic device of the presentinvention as positioned for taking a liquid sample from a catheter;

FIG. 2 is an elevational view, taken partly in section, of thediagnostic device of FIG. 1;

FIG. 3 is a fragmentary top view of a valve assembly, taken partly insection, in the diagnostic device of FIG. 1, with a handle in theassembly rotated 90 degrees;

FIG. 4 is a fragmentary sectional view taken substantially as indicatedalong the line 4--4 of FIG. 3;

FIGS. 5 and 5a are fragmentary elevational and sectional views,respectively, showing a valve element in the valve assembly of FIG. 3located at a first position;

FIGS. 6 and 6a are fragmentary elevational and sectional views,respectively, showing the valve element in the valve assembly of FIG. 3located at a second position;

FIGS. 7 and 7a are fragmentary elevational and sectional views,respectively, showing the valve element in the valve assembly of FIG. 3located at a third position;

FIG. 8 is a fragmentary sectional view of a swab attachment for thediagnostic device of FIG. 1; and

FIG. 9 is a fragmentary sectional view of another embodiment of a valveassembly for the diagnostic device of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 1 and 2, there is shown a diagnostic devicegenerally designated 20 having a hollow needle 22 for penetrating asource of a liquid sample, such as a source of urine through the wall ofa catheter C, a valve assembly 24 communicating with the needle 22, asyringe or pump means 26 having a chamber 28 communicating with thevalve assembly 24, and an elongated receptacle 30 having a cavity 32.The needle 22 has a hub 34 removably received on a stem 36 extendingforwardly from the valve assembly 24, such that the needle communicateswith a first passageway 38 in the stem 36, as best illustrated in FIGS.1-3. As shown in FIG. 2, an elongated cap 33 may be removably positionedon the needle 22 for covering and protecting the needle when the deviceis not in use. As best illustrated in FIGS. 1-3, the syringe 26 has anipple 40 received in a second passageway 42 in a second stem 44extending rearwardly from the valve assembly 24. The first and secondpassageways 38 and 42 are preferably aligned for a purpose which will bedescribed below. The valve assembly 24 has a third stem 46 having athird passageway 48 extending generally at right angles to the first andsecond passageways 38 and 42. Thus, the valve assembly 42 communicatesthrough the first passageway with the hollow needle 22, the secondpassageway 42 with the syringe chamber 28, and the third passageway 48with the container cavity 32.

As illustrated in FIGS. 3 and 5a, the valve assembly 24 has a bodymember 50 having a cylindrical bore 52 extending through the bodymember. The valve assembly also has a cylindrical valve member 54rotatably received in the bore 52, with the valve member 54 having aplug 56 adjacent one end to retain the valve member in the bore, and ahandle 58 adjacent the other end for rotating the valve member in thebore. The valve member 54 has a first channel 60 which extends throughthe valve member and which is aligned with the first and secondpassageways 38 and 42 when the handle and valve member are located at afirst position, as shown in FIGS. 5 and 5a. In this configuration of thevalve assembly 24, the handle 58 of the valve member 54 is directedalong the third stem 46, as shown in FIG. 5, and fluid communication isestablished between the needle and the syringe chamber through the firstchannel 60.

The handle 58 of the valve member 54 may be moved to a second positiondirected along the first stem 36, as shown in FIG. 6. In thisconfiguration of the valve assembly, a second channel 62, which extendsbetween the first channel 60 intermediate its ends and the outside ofthe valve member 54, communicates between the second passageway 42 andthe first channel 60, as shown in FIG. 6a, and the first channel 60communicates with the third passageway 48. Thus, in this configurationof the valve assembly, communication is established between the syringechamber and the container cavity.

The handle 58 of the valve member 54 may be moved to a third positiondirected along the third stem 44 of the valve assembly, as illustratedin FIG. 7. In this configuration of the valve assembly, communication isestablished between the needle and receptacle cavity through the firstpassageway 38, the second channel 62, the first channel 60, and thethird passageway 48, as shown in FIG. 7a. Accordingly, communicationbetween the needle and the syringe chamber, the syringe chamber and thecontainer cavity, and the needle and the container cavity may beselected by movement of the handle 58 of the valve member 54.

As shown in FIGS. 3 and 4, the body member 50 of the valve assembly hasa projection 64 extending toward the handle 58. A lug 66, which extendsoutwardly from the valve member 54, is located in a cutout portion 69intermediate first and second ends 68 and 70, respectively, of theprojection 64. The projection 64 and lug 66 cooperate in serving as stopmeans to limit movement of the valve member 54 in the body member 50.When the lug 66 engages against the first end 68 of the projection 64,the valve element is located at its second position, as shown in FIGS. 6and 6a , with its handle 58 directed along the first stem 36, and withthe valve assembly communicating between the syringe chamber and thecontainer cavity. When the lug 66 is engaged against the second end 70of the projection 64, the handle 58 is directed along the second stem 44of the valve assembly, with the valve assembly communicating between theneedle and the container cavity in its third position, as shown in FIGS.7 and 7a. When the lug 66 is positioned midway between the first andsecond ends 68 and 70 of the projection 64, the handle 58 is directedalong the third stem 46 of the valve assembly in its first position, asshown in FIG. 5, and the valve assembly communicates between the needleand the syringe chamber as best illustrated in FIG. 5a. Thus, the lug 66and projection 64 serve to limit movement of the valve member 54 in thebody member 50 between the second and third positions of the valveassembly.

As illustrated in FIGS. 1 and 2, the syringe 26 has a barrel 72 definingthe syringe chamber 28, and a plunger 74 received in the syringe chamber28 for reciprocation therein and pumping of liquid into and out of thechamber. A band 76 extends from a top wall 78 of the receptacle 30around the syringe barrel 72 to retain the syringe in position on top ofthe receptacle.

The receptacle 30 has a first outer portion 80 defined by the top wall78 and a depending side wall 82 extending peripherally around the topwall 78. A second inner portion 84 of the receptacle is removablyreceived in the outer portion 80, with a peripheral flange 86 of theinner portion engaging against the side wall 82 of the outer portion 80to retain the inner portion in the outer portion of the receptacle. Theinner portion 84 has a bottom wall 88 having a pair of compartments 90aand 90b separated by a partition 92. Different types of culture medium94a and 94b are located in the compartments 90a and b, respectively, asshown. The bottom wall 88 of the inner portion 84 has a step 96 adjacentan end of the inner portion 84 remote the third stem 46 of the valveassembly 24. An absorbent pad 98, such as a compressed cellulosematerial or a sponge, is positioned on the step 96 for a purpose whichwill be described below. The bottom wall 88 of the compartments 90a andb has a plurality of protuberances 100 to retain the culture media 94aand b in position in the compartments.

In preparation of the device for taking a sample, the inner portion 84of the receptacle 30 may be removed from the outer portion 80 throughuse of a tab 95 extending from one end of the inner portion 84, andappropriate media may be placed in the compartments. The inner portion84 of the receptacle may then be inserted into the outer portion untilthe flange 86 engages the side wall 82 of the outer portion 80. A fluidimpervious sheet 102, such as foil, may then be secured to an outwardlydirected flange 104 extending peripherally around the side wall 82 ofthe outer portion 80, such that the sheet 102 seals the inner portion 84inside the outer portion 80 of the receptacle, and prevents moistureloss from the receptacle cavity 32 and thus possible breaking up of themedia in the receptacle cavity.

The device may be used to collect a liquid sample as follows. The handle58 of the valve member 54 is moved to its first position, as shown inFIGS. 5 and 5a, such that the handle 58 is directed along the third stem46, and the cap 33 is removed from the needle. The needle 22 may then beused to penetrate the source of liquid sample. If the device is utilizedto obtain a urine sample from a catheter C, as shown in FIG. 1, bypenetrating the wall of the catheter with the needle, the catheter isfirst blocked below the site of the needle puncture to collect asufficient amount of urine in the catheter where the sample is to betaken.

Once the needle has penetrated the catheter wall, the plunger 74 of thesyringe is withdrawn from the syringe barrel 72 to withdraw urine fromthe catheter through the needle 22, the first passageway 38, the firstchannel 60, and the second passageway 42 into the syringe chamber 28.When a sufficient sample has been withdrawn from the catheter, thehandle 58 of the valve element 54 is moved to the second positiondirected along the first stem 36, as shown in FIGS. 6 and 6a, and theneedle 22 may be withdrawn from the catheter, if desired. Next, thebarrel 74 of the syringe 26 is pushed into the chamber 28 to pump thewithdrawn liquid sample through the second passageway 42, the secondchannel 62, the first channel 60, the third passageway 48 into thereceptacle cavity 32. As the liquid sample passes from the thirdpassageway 48 into the receptacle cavity 32, the third stem 46 directsthe liquid to one end of the culture media, after which it flows alongthe surface of the longitudinally aligned media 94b and 94a forinoculation thereof, with any excess liquid continuing to flow into theabsorbent pad 98 where it is absorbed and retained. Thus, any excessliquid is drawn off the surface of the culture media 94a and 94b, afterthe media 94a and b has been inoculated. If it is desired to obtain agreater quantity of liquid sample for inoculation of the media, theneedle may be retained in place through the wall of the catheter, whilethe valve element is repetitively moved between its first and secondpositions, and the syringe is repetitively pumped to withdraw liquidfrom the catheter and pump it into the receptacle cavity. In eitherevent, once the culture media has been inoculated by the liquid sample,the needle 22 may be removed from the first stem 36, and the receptaclepresents a convenient package for subsequent incubation of the media.After suitable incubation, the color attained by the media and thedensity of the bacterial colonies provide an indication of the amount ofbacteria which was initially present in the liquid sample for diagnosingthe sample.

It is thus apparent that the device of the present invention permitsimmediate inoculation of the culture media with the liquid sample in asimplified manner. The needle permits penetration of the liquid sourceand the device provides a closed system for inoculating the media withthe sample, thus preventing contamination of the sample. It is apparentthat the device of the present invention may be used for taking samplesof body fluids other than urine, such as blood, or spinal fluid, forinoculation of suitable media. It is also contemplated that the devicemay be used for diagnosing the body fluids of animals. The particularmedia 94a and b which is used in the receptacle is selected according tothe fluid to be diagnosed and bacteria to be detected. Suitable mediafor use in determining the bacteria count in urine samples is CLED andMacConkey. Similarly, suitable media for determining the bacteria countin a sample of spinal fluid are blood agar and chocolate agar. Mediauseful for determining the bacteria count in blood are blood agar andchocolate agar. It is also apparent that a single medium or more thantwo media may be used in the receptacle, if desired. If a liquid sampleis to be taken where the use of a syringe may be undesired, such as thespinal column, or the liquid sample is in an environment of sufficientlyhigh pressure, the handle 58 may be moved to the third position directedalong the second stem 44 of the valve assembly, as shown in FIGS. 7 and7a, such that communication is established between the needle and thereceptacle cavity. Thus, in this configuration of the valve member,fluid passes directly from the needle through the valve assembly to thereceptacle cavity for inoculation of the media.

For certain applications it is desirable to use the swab attachment 106,as shown in FIG. 9 in lieu of the needle. The attachment 106 has anelongated hollow member 108 having a passageway 110 extendinglongitudinally through the member 108. One end 112 of the hollow member108 is slightly flared and may be removably attached to the outer end ofthe first stem 36 of the valve assembly 24, such that the passageway 110of the hollow member 108 is in communication with the first passageway38 of the valve assembly 24. The hollow member 108 has a swab 104, suchas cotton, adjacent the other end 116 of the hollow member 108. Thehollow member 108 may be used in conjunction with the device of thepresent invention for obtaining a sample from the site of a wound asfollows. First, a liquid suspension solution, such as a saline solution,e.g., isotonic sodium chloride, is withdrawn into the syringe of thedevice, and ejected by the syringe to the swab and wound site, sincethere may not be a sufficient quantity of liquid initially present atthe site to obtain an adequate sample with the device. Once the solutionhas been ejected against the wound site, and the solution is mixed bythe swab with the sample to obtain suspension of the sample in liquidsolution. Next, the solution, which contains the suspended sample, iswithdrawn into the syringe and pumped into the receptacle cavity, aspreviously described, to inoculate the culture media.

Another embodiment of a valve assembly for the device of the presentinvention is illustrated in FIG. 10, in which like reference numeralsdesignate like parts. In this embodiment of the valve assembly, a firstone-way valve element 120, such as a flap valve, is positioned in thefirst passageway 38 of the first stem 36, such that the valve elementpermits liquid to pass through the first passageway to the secondpassageway 42, but prevents passage of liquid from the second and thirdpassageways 42 and 48 through the first passageway 38. A second valveelement 122 is located in the third passageway 48 of the third stem 46,such that liquid is permitted to pass from the second passageway 42through the third passageway 48, while liquid is prevented from passingthrough the third passageway 48 to the first or second passageways 38 or42. In use, when the needle or swab attachment has been located at thedesired position for obtaining a liquid sample, the plunger of thesyringe is withdrawn from the syringe barrel to withdraw liquid throughthe needle or swab attachment, the first valve element 120 in the firstpassageway 38, and the second passageway 42 into the syringe chamber. Atthe same time, the second valve element 122 prevents passage of liquidfrom the receptacle cavity to the syringe chamber. Next, the syringeplunger is pushed into the syringe barrel, and the withdrawn sample ispumped through the second passageway 42 and the second valve element 122into the receptacle cavity for inoculation of the culture media, whilethe first valve element 120 prevents passage of the pumped liquidthrough the first passageway 38 into the needle or swab attachment.

Thus, there has been described a diagnostic device for inoculatingculture media with a liquid sample in a simplified and asceptic manner,substantially immediately after the sample has been taken. During use,the needle or swab attachment serve to establish communication with theliquid sample, and the valve assembly or valve means separatelyestablishes communication of the needle or swab attachment and thereceptacle with the syringe.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

What is claimed is:
 1. A diagnostic device for a source of liquidsample, comprising:an elongated receptacle having a culture mediumlongitudinally disposed in a generally planar configuration along a wallof the receptacle; pump means connected intermediate the source andreceptacle; means in addition to the pump means for directing the samplefrom the pump means into the receptacle only adjacent one end of saidmedium for passage along the medium; and an absorbent pad locatedadjacent the other end of the medium remote from the directing means tocapture and retain excess liquid.
 2. The device of claim 1 wherein saidreceptacle includes a plurality of longitudinally aligned culture media,and the directing means directs the sample adjacent one end of thealigned media.